Cylinder Head Bolt Kit for Harley Davidson ’57-early ’73 XL’s

Cylinder Head Bolt Kit for Harley Davidson ’57-early ’73 XL’sHIGH PERFORMANCE SERIESHigh Performance head bolts are available with a reduced wrenching hex or 12 point and wide area flanged head that eliminates theneed for valve train removal to facilitate cylinder head retorquing. All High Performance Series bolts are 180,000 psi (which is 15%stronger than Grade 8) and kits come complete with hardened parallel ground washers. PROFESSIONAL SERIESAll Pro Series bolts are cold forged to ensure molecular integrity,

ARP Pro Series head bolt kits are application specific and designed to deliversuperior strength typically associated with competition engines

These materials are primarily used in connecting rods where extremely high loads

PROFESSIONAL SERIESAll Pro Series bolts are cold-forged to ensure molecular integrity

The big difference is in the shank design

You have a choice of black oxide finished 8740 chrome moly steel or polished ARP Stainless

Because ARP studs are manufactured to suchexacting tolerances

ARP studs are thread rolled after heat-treat

All in all

All kits come complete with hardened parallel-ground washers and high quality nuts

Your choice of chrome moly steel or polished stainless (nominally rated at 180

When the bolt hasstretched the specified amount

Because factory connecting rods (or aftermarket versions of OEM rods) are used in a variety of applications from rebuilt stock motors to modified powerplants used in circle track